UC-NRLF 


MMHMMMMMMMHMHMI 


GASOLINE  ENGINE 


ILLIAMS 


GIFT  OF 
:  H.. 


GASOLINE    ENGINE 
IGNITION 


BY 
E.    J.    WILLIAMS 


CINCINNATI 

The  Gas  Engine   Publishing  Co. 

BLYMYER  BUILDING 

1906 


Copyright,  1906 

by 

The  Gas  Engine  Publishing  Co 
Cincinnati,  Ohio 


uw 


PREFACE. 


From  observations  made  in  the  marine 
gasoline  engine  field,  the  purchaser  of  an 
outfit  is  usually  his  own  operator,  and  with 
him  alone  rests  the  responsibility  of  un- 
derstanding the  different  phases  attendant 
with  its  successful  operation.  Very  few 
books  have  been  written  which  render  as- 
sistance to  the  marine  gasoline  engine  op- 
erator, and  those  few  do  not  deal  point- 
edly with  the  ignition  system. 

Numerous  little  difficulties  are  mastered 
in  the  general  equipment,  but  occasionally 
information  is  wanted  regarding  the  elec- 
trical outfit,  its  installation  or  principle  of 
operation.  With  this  end  in  view,  the  au- 
thor 'has  endeavored  to  treat  this  work  in 
a  simple  and  non-technical  manner,  basing 
its  contents  on  the  assumption  that  the 
reader  is  a  novice  in  every  sense  to  which 
the  word  implies,  and  trusts  its  perusal  will 
meet  with  a  favorable  reception. 

E.  J.  WILLIAMS. 

4G4557 


CONTENTS. 


I.  Magnetism 1 

II.  Make-and-Break  Ignition 4 

III.  Jump  Spark  Ignition 16 

IV.  Batteries 36 

V.  Generators  . . 47 

VI.  Testing  for  Trouble 56 

VII.  Kinks  in  Power  Installation . .  68 

VIII.  Horsepower  . . 74 

IX.  Wiring  Diagrams 81 


CHAPTER  I. 

MAGNETISM. 

The  average  person  naturally  understands 
nothing  regarding  electricity,  and  the  oni) 
accessory  about  a  gasoline  engine  in  which 
he  has  no  confidence  is  this  particular  part. 

A  wire,  when  charged  with  an  electrical 
current,  contains  a  property  adverse  to  the 
natural  state  of  the  wire  when  not  electri- 
fied. When  a  wire  has  an  electrical  current 
flowing  through  it,  magnetic  lines  of  force 
surround  it  to  a  distance  consistent  to  the 
strength  of  the  current.  If  the  wire  is 
wound  in  a  circular  form,  in  layers,  forming 
a  coil,  the  magnetic  lines  of  force  are  in- 
creased in  strength,  and  if  wound  around  a 
bar  of  soft  iron  an  additional  increase  is 
gained. 

If  a  bar  of  soft  iron  is  wound  with  several 
turns  of  insulated  (covered)  copper  wire, 
and  a  current  of  electricity  passed  through 
the  wire,  either  from  a  dynamo  or  batter j, 


A?:4>IO"IL.i.- 


the  bar  becomes  saturated  with  a  property 
called  magnetism,  and  is  capable  of  attract- 
ing particles  of  steel  as  long  as  the  electricity 
flows  through  the  wire,  and  ceases  immedi- 
ately, when  the  wires  are  disengaged  and 
the  current  flow  stopped.  When  the  bar 
of  iron  is  magnetized,  one  end  will  attract 
steel  while  the  other  end,  will  repel  it. 

Induction  or  jump  spark  coils  and  any 
electrically  operated  mechanism  such  as  dy- 
namos, magnetos,  etc.,  are  based  on  the 
principles  or  phenomena  of  electro  magnet- 
ism as  above  stated. 

A  permanent  magnet  is  a  piece  of  spe- 
cial steel,  stored  or  saturated  with  mag- 
netism for  an  indefinite  time.  It  will  per- 
from  the  duties  of  an  electro  magnet  in  many 
instances.  Permanent  magnets  are  utilized 
for  the  construction  of  magnetos,  and  the 
magnetism  contained  in  the  metal  lasts  gen- 
erally from  5  to  10  years,  according  to  the 
grade  and  work  the  magneto  performs. 

In  order  to  first  saturate  the  steel  with 
magnetism,  it  is  necessary  to  lay  it  on  a  di- 
rect current  dynamo  of  motor,  or  rub  it 
on  what  was  originally  called  a  load  stone 
(another  permanent  magnet).  When  the 


magnetism  becomes  weak  the  same  method 
of  charging  is  again  repeated. 

Electric  current  requires'  some  standard 
of  measurement,  therefore  it  is  expressed 
in  volts  and  amperes.  A  volt  is  the  unit  of 
pressure  or  strain,  and  is  similar  to  the 
pressure  of  steam  in  a  boiler,  or  air  in  a 
tank  expressed  in  pounds. 

An  ampere  is  the  unit  rate  of  flow  or 
amount  backing  up  the  volt,  and  compares 
with  the  amount  drained  from  the  above 
referred  to  boiler  or  air  tank.  If  a  tank  or 
boiler  had  100  pounds  pressure  and  dis- 
charged the  whole  contents  at  once,  the 
rate  of  flow  would  correspond  to  the  flow 
from  a  battery  on  short  circuit,  and  to  dis- 
charge at  a  low  rate  for  a  length  of  time, 
would  correspond  to  the  drain  from  a  bat- 
tery through  a  coil  or  otherwise. 

The  drop  in  pressure  during  this  opera- 
tion corresponds  to  the  drop  in  volts  when 
using  a  battery. 


CHAPTER  II. 

MAKE-AND-BREAK    IGNITION. 

Electrical  ignition  for  gasoline  engines 
is  of  two  kinds,  make-and-break  and  jump 
spark. 

In  mechanical  make-and-break  ignition 
a  coil  is  utilized,  through  which  a  current 
of  electricity  is  passed,  the  coil  intensifying 
the  current  to  such  an  extent  that  a  very 
hot  spark  follows  the  terminals  of  the  wires 
if  they  are  separated  or  the  two  ends 
touched  together  and  drawn  apart.  This 
action  or  spark  is  caused  for  a  short  period 
by  the  self-inductance  or  reaction  of  the 
current  remaining  in  the  circuit  after  it  is 
broken ;  that  is,  when  the  terminals  are  sep- 
arated. This  spark  occurs  only  as  the 
wires  are  separated,  after  the  current  or 
circuit  is  completed  through  the  coil,  and 
does  not  occur  at  the  time  connection  is 
made  or  completed. 

In  making  use  of  this  system  of  ignition 
in  gasoline  engines,  a  means  for  sepa- 


rating  these  two  ends  or  break  in  ths 
circuit  is  necessary,  to  throw  the  spark  in 
the  combustion  chamber.  To  this  end  one 
electrode  is  made  stationary,  the  other  mov- 
able, to  touch  and  complete  the  circuit  and 
move  away  from/  the  stationary  electrode  or 
terminal.  The  stationary  member  is  there- 
fore constructed  in  the  form  of  a  plug,  in- 
sulated from  the  engine  by  a  mica,  or  porce- 
lain, bushing,  or  any  non-conducting  ma- 
terial. A  sectional  miake-and-break  plug 
or  spark  pin  is  shown  in  Figure  i. 

To  the  point  within  the  cylinder  or  ex- 
plosive chamber,  A,  is  affixed  a  small  piece 
of  platinum,  iridium  or  other  non-oxidizing 
composition.  Very  often  steel  points  are 
used,  but  carbonation  and  oxidation  are  so 
rapid  that  brightening  the  contact  points 
has  to  be  resorted  to  very  often.  B  shows 
the  insulation  of  mica,  C  the  casing  or 
sleeve  to  screw  into  the  firing  chamber,  and 
D  the  wire  terminal  or  binding  post. 

It  will  thus  be  readily  seen  that  when  the 
plug  is  screwed  into  the  'cylinder,  A  has 
no  communication  metallically,  other  than 
with  the  wire  and  when  the  mlovable  elec- 
trode comes  into  action.  The  other  end  or 


D 


Fig 


wire  from  the  battery  leads  to  the  ground, 
as  shown  in  Figure  2.  This  movable  part 
is  mechanically  actuated  by  eccentric,  cam, 
gear,  crank,  by  the  movement  of  the  piston 
within  the  cylinder  or  any  other  means  pos- 
sible. 

In  a  two-cycle  engine  the  mechanical  ap- 
paratus is  arranged  to  spark  every  revolu- 
tion of  the  fly  wheel,  and  in  a  four-cycle 
every  other  revolution,  considering  a  single- 
cylinder  engine  in  both  instances. 

The  action  of  the  system  as  represented 
in  Figure  2  is  as  follows :  The  electric  cur- 
rent from  the  batteries,  A,  is  flowing 
through  the  intensity  or  spark  coil,  B,  to  the 
plug,  C,  in  the  cylinder  head,  through  the 
movable  electrode,  E,  if  it  touches  the  insu- 
lated plug,  C,  and  returning  through  the 
ground,  D,  to  the  batteries,  A,  again.  As 
the  lever,  F,  is  actuated  upward  by  the  rod, 
the  circuit  is  closed  by  the  movable  electrode, 
E,  touching  the  stationary  electrode,  C.  Sep- 
arating them  again  as  the  rod  drops  causes 
a  spark  to  follow  the  points  for  a  fraction 
of  a  second,  which  ignites  the  gas  in  the 
cylinder,  forcing  the  piston  on  its  downward 
stroke. 


The  spark  coil  used  for  this  system  con- 
sists of  a  single  winding  of  wire,  in  sev- 
eral layers ;  in  reality,  an  electro  magnet. 
A  bunch  of  soft  iron  wires  is  tightly  bound 
together,  and  a  piece  of  wood  placed  over 
each  end,  thereby  making  a  sort  of  spool. 
On  this  spool,  around  the  core  of  soft  iron 
wires,  several  layers  of  No.  14  or  16  wire 
are  wound.  After  finishing  the  winding 
process  each  end  of  the  wire  is  made  fast 
to  a  binding  post,  and  the  whole  mast 
dipped  in  molten  paraffine  wax  and  left  to 
dry,  when  it  is  ready  for  use. 

Different  length  coils  are  used  and  man- 
ufactured, varying  in  size  from  10  inches 
long  and  1^2  inch  in  diameter  to  4  inches 
long  and  5  inches  in  diameter.  It  has  often 
been  claimed  that  the  short  coil  and  core 
gives  the  better  result,  because  the  core  be- 
comes magnetized  and  reacts  quicker,  giv- 
ing a  quick  response  to  the  opening  and 
closing  of  the  circuit,  and  that  the  long 
core  coil  lags  somewhat  for  high  speed. 
Whether  this  is  ever  noticeable  is  only  a 
matter  of  conjecture  and  theory,  as  no  dif- 
ference can  be  discovered  in  the  speed  of  the 
engine  if  the  short  coil  is  used,  and  suddenly 


switched  over  to  a  long  coil,  and  when  hav- 
ing a  tachometer  or  revolution  counter  at- 
tached. 

Figure    3    gives    a   sectional   view   of  a 
make-and-break  spark  or  intensity  coil.    A 


Fie  3 


is  the  core,  B  the  winding  and  C  the  bind- 
ing posts  for  attaching  wires.  This  form 
of  coil  was  Originally  made  use  of,  and  is 
even  utilized  at  the  present  time  for  elec- 
tric gas  lighting. 


10 


Magnetic  primary  igniters  are  now  nid.i- 
ufactured  to  screw  into  the  combustion 
chamber,  requiring  no  mechanical  move- 
ment or  attachment  to  operate.  This  form 
is  a  compact  combination  of  both  electrodes 
and  a  spark  coil,  although  by  the  addition 
of  a  make-and-break  spark  coil  into  the  cir- 
cuit a  larger  and  hotter  spark  is  realized. 
The  principle  of  this  type  is  more  readily 
understood  by  referring  to  Figure  4. 

When  the  timer,  C,  such  as  is  utilized 
for  jump  spark  ignition,  closes  the  circuit 
from  the  batteries,  B,  current  flows  through 
the  electro  magnets,  A,  insulated  plug,  G, 
points^,  E,  and  to  the  ground  in  the  engine 
frame.  As  soon  as  the  current  magnetizes 
the  electro  magnets,  A,  the  lever,  F,  is  at- 
tracted by  the  core,  D,  separating  the  elec- 
trodes or  spark  points,  E,  causing  a  spark 
to  follow  their  separation.  Their  separa- 
tion breaks  the  circuit,  causing  the  lever, 
F,  to  return  to  G,  by  the  action  of  the 
spring,  closing  the  circuit  again  at  the  elec- 
trodes, E.  As  soon  as  connection  is  made 
again  at  E,  the  same  operation  is  repeated, 
if  the  timer  is  still  closing  the  circuit.  This 
operation  is  so  rapid  that  a  series  of  rapid 


11 


<D 


Fig--* 


12 


sparks  is  made  each  time  the  engine  timer 
closes  the  circuit. 

Figure  5  gives  a  drawing  of  a  primary 
spark  plug  in  its  compact  form). 


Ffc.  5 

SPARK  ADVANCE. 


The  advance  or  retarding  of  the  spark 
in  the  cylinder  is  a  convenient  method  of 
speeding  up  or  slowing  down  the  engine. 
Means  to  advance  and  retard  the  spark 


13 


while  the  engine  is  running  is  not  found 
on  all  make-and-break  spark  devices.  The 
meaning  of  spark  advance  is  the  occurring 
of  the  spark  at  an  earlier  part  of  the  revo- 
lution or  stroke  of  the  piston.  For  exam- 
ple, if  the  spark  occurred  after  the  piston 
had  reached  its  top  dead  center,  and  had 
started  on  its  downward  stroke,  it  would 
be  called  a  late  spark,  or  negative  lead,  or 
that  the  spark  was  retarded.  If  after  the 
engine  is  running,  outside  means  are  avail- 
able to  cause  the  spark  to  fire  the  charge 
nearer  to  the  piston's  top  center,  or  before 
it  reaches  its  top  center,  on  the  compres- 
sion stroke,  it  would  be  called  advancing 
the  spark,  or  that  the  engine  had  an-  early 
spark,  or  positive  lead,  and  would  cause 
the  engine  to  speed  up  proportionately  to 
the  distance  in  the  revolution  the  spark 
had  advanced  from  its  first  position. 

The  spark  advancing  apparatus  in  mlake- 
and-break  ignition  is  generally  operated  by 
a  small  lever,  acting  so  as  to  trip  the  out- 
side device  earlier  in  the  stroke  after  start- 
ing. This  form  is  typical  of  the  two-cycle 
engine  with  this  system.  On  the  four- 
cycle engine  a  worm  gear  on  a  separate 


14 


shaft  with  the  ignition  device  causes  trie, 
cams,  eccentrics  or  shaft  containing  this 
device  to  twist  ahead  of  the  gears  thereon. 

In  jump  spark  system  of  ignition  the 
spark  is  advanced  or  retarded  by  the  move- 
ment of  the  case,  around  the  cam  or  arm, 
which  acts  on  the  contacts. 

The  four-cycle  engine  behaves  better 
with  a  negative  lead  when  throttling  the 
mixture  to  slow  down,  than  the  two-cycle 
engine  does.  Under  such  conditions  with 
the  latter,  crank  case  or  base  explosions  oc- 
cur, which  will  not  stop  until  the  spark  is 
advanced. 


15 


CHAPTER  III. 

JUMP   SPARK   IGNITION. 

The  jump  spark  system  of  ignition  is 
very  seldom  thoroughly  understood,  even 
by  persons  in  daily  contact  with  gasoline 
engines  fitted  with  this  equipment. 

If  a  current  of  electricity  from  a  battery 
is  passed  through  a  wire,  completing  the 
circuit,  and  another  wire  is  placed  near  it, 
without  battery  connection,  forming  anoth- 
er circuit,  an-d  having  no  metallic  contact 
with  the  former,  a  current  of  induced  na- 
ture will  occur  in  the  circuit  without  battery 
every  timie  the  electrified  circuit  is  opened 
and  closed. 

C  D 


Fig.  6 

Figure  6  explains  the  principle  referred 
to. 


16 


To  derive  a  strong  current  in  the  induc- 
tion current,  which  is  called  the  secondary, 
the  battery  circuit  or  primary  circuit  is 
wound  in  the  form  of  a  coil  over  a  soft  iron 
core,  thereby  making  an-  electro  magnet, 
and  over  the  primary  is  wound  hundreds 
of  turns  of  very  fine  wire  to  make  a  very 
strong  current  emanate  from  the  secondary 
winding.  This  form  completed  thus  far  is 
called  an  induction  coil  or  transformier,  the 


.1/1.1 

fro— - 


principle  of  which  is  shown  in  Figure  7. 
The  heavy  lin-es  are  the  primary,  the  fine 
lines  the  secondary  and  the  straight  lines 
from  left  to  right  the  core. 

The  jump  spark  coil  is  a  combination  of 
an  induction  coil  and  a  condenser,  and  with 
or  without  a  vibrator.  The  proper  name 
for  this  type  of  coil  is  Rhumkorf  coil,  and 
before  its  advent  into  the  gas  engine  field 


17 


it  was  used  for  multiple  gas-lighting  appa- 
ratus and  experimental  purposes.  Present 
uses  for  which  it  is  utilized  are  for  X-rays 
and  wireless  telegraphy,  but,  of  course,  in 
very  large  sizes,  at  an  expenditure  of  sev- 
eral thousand  dollars  each. 

The  only  difference  in  the  jump  spark 
ignition  coil  from  the  original  Rhumkorf 
coil  is  in  its  compact  and  water-proof  ar- 
rangement. 

As  before  mentioned,  the  induced  cur- 
rent in  the  secondary  circuit  occurs  only 
for  an  instant  as  the  primary  circuit  is 
opened  and  closed,  consequently,  to  produce 
a  pulsating  current  in  the  secondary  of  any 
duration,  some  means  must  be  had  to  au- 
tomatically open  and  close  the  primary  cir- 
cuit. It  is  for  this  reason  that  a  vibrator 
is  used  and  operated  by  the  magnetism  in 
the  iron  core  of  the  coil. 

Figure  8  represents  a  vibrator,  and  shows 
the  contact  points  for  making  and  opening 
the  circuit. 

The  principle  of  jump  spark  ignition  is 
the  jumping  of  the  induced  or  secondary 
current  across  the  terminals-  or  ends  of  the 
secondary  wires,  called  a  spark  gap,  utilized 


18 


in  the  form  of  a  plug,  with  stationary  termi- 
nals set  about  1-16  inch  apart.  The  plug, 
as  is  well  known,  screws  into  the  combus- 
tion chamber  of  the  engine  to  fire  the  charge 
of  explosive  mixture,  by  the  spark  jumping 


Pig.  8 


across  the  air  space  between  the  points. 

An  electrical  condenser,  previously  re- 
ferred to,  is  an  apparatus  that  charges  and 
discharges  itself  from  a  galvanic  or  battery 


19 


circuit.  Without  the  aid  of  a  condenser  no 
spark  would  be  visible  at  the  secondary  ter- 
minals. A  condenser  is  constructed  of  al- 
ternate sheets  of  tin  foil  and  wax  paper, 
every  odd  number  of  sheets  having  a  termi- 
nal connecting  to  one  side  of  the  vibrator, 
an-d  every  even  numbered  sheet  to  the  other 
side  of  the  vibrator.  The  mass  of  sheets 


Fig    9 

is   generally  placed   in  the  bottom  of  the 
coil  case  under  the  coil. 

Figure  9  is  a  diagrammatical  explanation 
of  a  condenser's  construction.  By  this 
method  of  connecting,  as  the  primlary  cir- 
cuit is  closed,  the  condenser  is  charged,  and 
as  the  vibrator  breaks  the  circuit,  the  con- 


20 


tents  are  discharged,  forcing  the  high  volt- 
age to  jump  across  the  secondary  terminals 
at  the  spark  plug  in  the  form  of  a  flame. 

Without  the  aid  of  the  condenser  the  cur- 
rent would  also  intensify  through  the  pri- 
mary winding,  in  the  .same  manner  as  it 
does  through  the  primary  or  make-and- 
break  coil,  causing  a  very  large  hot  spark  at 
the  vibrator  contacts. 

Calculations  have  been  made  by  a  num- 
ber of  electrical  experts  that  from  8,000  to 
10,000  volts  are  required  to  cause  the  sec- 
ondary current  to  jump  across  an  air  space 
of  1-16  inch.  In  an  internal  combustion 
engine,  with  the  gas  compressed,  thereby 
further  resisting  the  current,  it  can  be  read- 
ily seen  that  a  greater  voltage  will  be  re- 
quired under  these  conditions. 

The  average  voltage  emitting  from  the 
secondary  terminals  of  the  ordinary  jump 
spark  coil  varies  fromi  20,000  to  30,000,  ac- 
cording to  the  method  and  care  exercised  in 
its  manufacture. 

Extreme  care  must  be  exercised  in  wind- 
ing the  secondary,  in  the  insulation  be- 
tween primary  and  secondary,  and  in  cal- 
culating the  various  parts.  The  iron-  en- 

21 


tering  into  the  construction  of  the  core  must 
contain  great  permeability  and  retentive 
power,  because  the  voltage  of  the  secondary 
winding  i&  proportional  to  the  amount  of 
magnetism  destroyed  in  the  core  by  the 
opening  of  the  primary  circuit. 

The  construction  of  a  jump  spark  coil  is 
as  follows :  A  soft  iron  core  is  first  made 
by  cutting  a  lot  of  No.  1 6  or  18  gauge 
iron  wire  into  the  desired  length.  Enough 
of  these  wires  are  cut  to  fill  an  iron  pipe, 
•the  interior  of  which  is  the  .size  of  the  de- 
sired core.  After  filling  the  pipe,  both  ends 
are  plugged  with  clay,  and  the  whole  mass 
placed  in  a  coal  fire  and  allowed  to  remain 
there  until  the  fire  dies  out  and  the  pipe  is 
cold.  The  wires  are  then  removed  from 
the  pipe  and  each  one  wiped  off  to  remove 
the  oxide.  They  are  then  placed  in  hot 
water,  wiped  dry  and  each  one  separately 
coated  with  shellac.  When  thoroughly  dry 
they  are  again  bunched  ^  together,  bound 
with  a  light  piece  of  brass  wire  and  held 
in  place  by  a  drop  of  solder. 

This  method  of  construction  is  used  in 
the  manufacture  of  the  high  price  coils. 
In  other  grades  of  coils,  the  wires  are 

22 


bunched  together  without  washing  or  s pel- 
lacing,  arid  dipped  in  molten  paraffine  wax. 

Over  the  core  is  slipped  a  hard  rubber 
tube,  or  a  waxed  paper  mailing  tube,  and 
over  the  length  of  the  tube  is  wound  two 
layers  of  No.  18  B.  &  S.  gauge  single  cot- 
ton covered  magnet  wire  for  a  primary 
winding.  This  primary  winding  is  then 
given  a  wax  bath  and  another  tube  is 
slipped  over  this  winding.  Over  this  tube 
is  slipped  the  secondary  winding,  consist- 
ing of  from  y2  to  i  pound  of  No.  36  or  38 
silk  covered  magnet  wire,  in  two  or  more 
sections,  previously  wound  on  a  form  and 
soaked  in  wax  until  the  bubbles  ceased  to 
rise  to  the  surface,  to  hold  it  intact  and 
thoroughly  insulate  each  layer.  The  con- 
denser and  coil  are  then  placed  in  the  case, 
the  necessary  [cor-nections  made?  and  the 
box  rilled  with  molten  paraffine  wax. 

Cotton-covered  magnet  wire  is  often  used 
for  the  secondary  coil,  but  its  insulating 
properties  are  inferior  to  the  silk-covered 
wire. 

In  making  up  the  condenser,  attention 
must  be  given  to  the  grade  of  tin  foil  and 
paper  or  mica,  whichever  is  used.  The 


23 


Jl 


m-  m  m\  m  ^  m  m\  m 


M 


24 


latter  must  be  free  from  pin  holes,  and 
perfectly  dry,  and  the  number  and  size  of 
sheets  of  each  accurately  determined. 

Figure  10  shows  the  general  style  of  vi- 
brating coil  in  use  for  ignition  purposes, 
and  a  sectional  view  of  the  interior. 

Coils  are  made  vibrating  and  non-vibrat- 
ing, the  former  having  a  small  vibrator  at- 
tached to  the  case,  with  the  core  of  the 
coil  protruding  slightly  through  the  end 
of  the  case,  as  shown  in  Figure  10,  and 
non-vibrating,  as  its  name  implies,  has  no 
vibrator.  Each  break  of  .the  timer  on  the 
engine,  when  using  the  latter  coil,  produces 
one  spark  across  the  spark  plug  terminals, 
the  same  as  one  vibration  of  the  vibrator 
on  a  vibrating  coil. 

Vibrators  are  in  circuit  with  the  primary 
winding  and  battery,  and  the  vibrations  per 
minute  can  be  adjusted  by  the  thumb  screw 
contact. 

In  operation  the  action  of  a  jump  spark 
coil  is  as  follows ;  see  Figure  1 1 : 

As  the  primary  circuit  is  closed  by  the 
timer,  A,  the  condenser,  B,  is  charged  and 
the  core,  C,  is  magnetized,  attracting  the 
vibrator,  D.  When  the  vibrator,  D,  moves 


25 


CQ 


26 


toward  the  core,  C,  the  circuit  is  broken 
between  the  thumb  screw  point,  E,  and  the 
point,  F,  on  the  vibrator.  The  magnetism 
in  the  core  ceases  when  the  circuit  is  brok- 
en, the  condenser,  B,  discharges,  forcing 
a  high  voltage  through  the  secondary,  H, 
and  across  the  points  of  the  gap  or  plug, 
J,  in  the  form  of  a  spark.  As  soon  as  the 
circuit  is  broken  at  the  vibrator,  I},  demag- 
netizing the  core,  C,  the  vibrator  returns 
to  its  original  position,  and  closes  the  cir- 
cuit again  between  the  contact  screw,  E, 
and  the  vibrator  point,  F,  causing  a  repeti- 
tion of  the  operation.  This  making  and 
breaking  of  the  circuit  is  very  rapid,  caus- 
ing a  series  of  sparks  at  the  plug  terminals 
as  long  as  the  timer  keeps  the  circuit  of  the 
primary  closed. 

Chapter  IX  gives  the  scheme  for  connect- 
ing up  the  various  coils. 

SPARK  PLUGS. 

Generally  speaking,  spark  plugs  cause 
the  most  annoyance  of  any  apparatus  in 
the  jump-spark  system.  The  points  be- 
come clogged  with  carbon,  or  the  insula- 
tion breaks  down  or  cracks. 


27 


Figures  12,  13  and  14  show  several  forms 
of  spark  plugs  in  use.  A  is  a  plug  with 
central  insulation  of  porcelain-,  held  in  po- 
sition by  a  shoulder  or  enlargement  in  the 
center,  set  up  by  the  gland,  G.  The  ter- 


Fie    12 

minal  is  screwed  on  the  center  rod  and  is 
fitted  with  a  wing  nut  to  fasten  the  wire 
terminal.  One  bent  wire  is  fastened  in  the 
threaded  portion  or  ground  side,  while  the 
other  bent  wire  is  an  extension  of  the  cen- 
ter insulated  rod. 


B  shows  a  mica  insulated  plug,  with  the 
mica  tapered    the    whole    length^    held    in 

place  by  the  thumb  screw  set  nut,  N.  The 
thumb  screw  binding  post,  P,  is  vibratior> 
proof  against  movement  by  being  split  lon- 


-   T 


Fig-  13 

gitudinally,  to  be  drawn  together  by  the  set 
screw  S,  binding  the  threads  of  the  screw 
head. 

Figure  13  shows  a  mica  insulated  reversi- 
ble plug,  both  ends  of  which  are  alike,  and 


29 


either  end  can  be  screwed  into  the  cylin- 
der. The  end  not  used  in*  the  cylinder  is 
fitted  with  a  metal-threaded  cap,  M,.  The 
spark  may  be  made  to  jump  across  both  ends 
at  once,  the  outside  end  acting  as  a  spark 
gap.  A  wire  terminal,  T,  is  furnished  with 


Fig.  M 

each   plug,   and   makes   the   connection   by 
screwing  the  cap  against  the  terminals. 

Figure  14  is  a  two-terminal  plug,  and 
does  not  utilize  a  ground.  It  has  a  flange 
set  up  on  the  cylinder  with  bolts,  and  does 
not  screw  into  the  cylinder  in  the  same  man- 

30 


ner  as  an  ordinary  spark  plug.  With  the 
two-terminal  plug  both  wires  from  the  -sec- 
ondary of  the  coil  are  connected  to  the 
plug.  With  the  ordinary  plug  one  wire  is 
grounded  on  the  engine  frame. 

AUXILIARY    SPARK    GAPS. 

A  spark  gap,  as  before  mentioned,  is  the 
space  between  the  ends  or  terminals  of  the 
secondary  circuit.  The  space  between  the 
points  of  a  spark  plug  is  a  spark  gap.  An 
auxiliary  spark  gap  is  another  break  or  gap 
in  the  circuit  leading  to  the  plug.  The  aux- 
iliary gap,  unless  integral  with  the  plug,  is 
arranged  with  terminals  or  binding  posts 
for  the  wire  connections.  At  the  present 
time  the  utility  of  the  auxiliary  spark  gap 
appears  to  be  a  matter  of  question.  The 
reason  of  its  use-  is  the  claim/  of  its  tendency 
to  break  down  or  prevent  a  soot  bridge  be- 
tween the  plug  terminals,  and  also  to  per- 
mit an  outside  observation  of  each  spark 
on  a  secondary  wire. 

For  use  in  a  cabin  power  boat,  the  open 
type  would  not  be  altogether  exactly  safe, 
should  a  gasoline  leak  occur  while  the  en- 
gine was  running. 


31 


Figure  15  shows  a  spark  gap  enclosed 
in  a  glass  tube,  which  is  utilized  to  a  great 
extent  on  automobiles.  At  each  end  the 


Fig.  15 

holes  in  the  case  are  for  screwing  to  the 
woodwork  at  any  point,  and  the  thumb 
screws  are  for  fastening  the  secon-dar> 
wires. 

TIMERS. 

A  timer  is  an  apparatus  generally  used 
in  connection  with  a  jump  spark  coil,  and 
is  connected  in  the  primary  circuit  to  close 
the  latter  at  the  proper  point  in  the  cycle 
to  discharge  the  secondary  in  the  form  of 
a  spark  across  the  spark  plug  terminals  in 
the  cylinder.  Timers  are  also  called  com- 
mutators and  distributers. 

Figure  16  shows  a  timer  used  for  clos- 
ing the  primary  circuit  of  a  four-cylinder 
jump  spark  coil.  If  the  engine  is  a  two- 
cycle,  the  timer  is  set  on  the  crank  shaft 


32 


o 


Fig.  16 

33 


or  a  smaller  lay  shaft,  revolving  at  the 
same  speed  as  the  crank  shaft.  If  the  en- 
gine is  of  the  four-cycle  type,  the  arm  of 
the  timer  is  keyed  on  the  cam  shaft,  which 
is  rotated  by  a  2-to-i  gear;  that  is,  the 
timer  rotates  once  to  the  crank  shaft's  two 
revolutions. 

The  arm  being  fastened  to  the  cam  shatt, 
it  revolves  with  same,  touching  each  con- 
tact block  during  its  course.  Un-der  each 
contact  block  a  spring  is  arranged  to  al- 
low the  block  to  be  forced  down  in  the 
square  socket  in  the  center  of  the  circle  or 
disk,  giving  a  friction  contact  between  the 
block  and  rotating  arm.  The  back  of  each 
block  is  metallically  connected  to  a  binding 
post  for  the  primary  wire  connection  to 
its  respective  coil.  When  the  arm  touches 
any  contact  block,  a  circuit  is  established 
to  the  ground  through  the  arm  to  the  en- 
gine frame,  to  the  battery  and  through  the 
primary  winding  and  vibrator,  returning  to 
the  contact  block. 

The  arm  extending  upward  from  the 
back  of  the  timer  case  is  attached  to  the 
latter  and  is  for  attachment  to  a  spark  ad- 


34 


vancing  lever,  to  advance  or  retard  the 
spark  while  the  engine  is  in  operation. 

Several  commutators  or  distributers  are 
now  on  the  market  to  distribute  the  second- 
ary current  to  more  than  one  cylinder  at 
the  proper  time,  by  the  use  of  but  one  coil. 
With  this  style  the  "buzzer"  or  vibrator  is. 
kept  in  operation  all  the  time.  The  strain 
in  the  coil  is  greater  and  the  insulation 
must  be  perfect  for  this  system. 

Another  form  distributes  the  secondary 
and  makes  a  primary  contact  at  the  same 
time,  both  forms  involved  in  one  casing. 


35 


CHAPTER  IV. 

BATTERIES. 

There  are  two  sources  of  electricity  for 
ignition  of  gas  en-gines,  viz.,  battery  and 
generator. 

Batteries  are  divided  into  two  classes, 
primary,  which  generates  current  by  its 
own  chemical  action,  and  secondary,  which 
requires  a  current  of  electricity  to  be 
turned  into  it  for  a  given  time,  and  dis- 
charges a  current  for  a  slightly  less  time 
than  was  occupied  in  charging. 

PRIMARY  BATTERIES. 

Primary  batteries  are  used  to  a  greater 
extent  than  secondary  batteries  for  ignition 
purposes.  The  dry  battery,  sal  ammoniac 
and  soda  types  are  all  primary,  while  stor- 
age or  secondary  are  mostly  made  up  of 
lead  plates  and  diluted  acid. 

Dry  batteries  are  used  extensively,  be- 
cause of  their  convenience,  and  are  prac- 
tically the  sal  ammoniac  wet  battery  in  paste 


36 


iK.  17 


37 


form.  The  outside  shell  is  the  zinc  element 
and  the  center  connection  the  carbon. 
Chemicals  are  introduced  in  a  paste  or  by 
saturating  some  absorbing  material  such  as 
blotting  paper,  etc.,  and  sealed  at  the  top 
with  pitch.  The  average  size,  2^/2  inches 
by  7  inches,  gives  1.30  to  1.50  volts  and 
from  12  to  15  amperes,  and  larger  sizes 
give  the  same  voltage,  but  greater  am- 
perage. When  a  dry  battery  becomes  ex- 
hausted it  is  more  economical  to  discard 
it  than  to  try  some  miethod  of  reviving  or 
recharging. 

SAL  AMMONIAC  BATTERY. 

Sal  ammoniac  (wet)  batteries,  consist- 
ing of  zinc,  carbon  and  a  solution  of  sal 
ammoniac  can  be  recharged  by  renewing 
the  liquid,  and  if  zincs  are  extremely  thin 
or  badly  eaten  away,  new  ones  can  be  put 
in.  The  carbon  element  should  last  in- 
definitely, but  should  a  battery  of  this  type 
fail  to  give  a  satisfactory  current  after  re- 
charging, and  connections  have  been  looked 
over  and  found  to  be  all  right,  the  carbon 
element  has  in  all  probability  become 
clogged  in-  the  pores  and  requires  cleaning. 
To  do  this  it  should  be  removed  from  the 


38 


Fig.  18 
Sal  Ammoniac  Battery. 


39 


jar,  and,  if  it  is  a  hollow  cylinder  with  a 
small  plug  in  the  top,  the  contents  of  granu- 
lated carbon  should  be  thrown  away.  The 
carbon  cylinders  should  then  be  placed  in 
a  pot  or  pan,  filled  with  water  to  cover 
them,  and  placed  over  a  fire,  keeping  the 
water  boiling  for  an  hour  or  two.  After 
this  boiling-out  process  new  granulated 
carbon  should  be  placed  in  the  cylinder. 
This  will  in  all  probability  remedy  the 
trouble,  but  in  case  it  fails  new  carbons  will 
have  to  be  purchased. 

When  purchasing  zincs  for  this  type, 
have  the  local  druggist  amalgamate  them, 
and  they  will  be  found  to  last  a  great  deal 
longer.  If  salts  from  the  liquid  creep  over 
the  tops  of  jars,  immerse  the  tops  for  about 
an  inch  in  tnblten  paraffins  wax  until  a  de- 
posit is  left. 

Dry  batteries  and  sal  ammoniac  wet  bat- 
teries are  called  "open  circuit"  batteries  be- 
cause the  work  which  they  are  called  upon 
to  do  is  of  an  intermittent  nature,  and  the 
voltage  is  not  constant  until  exhausted. 
After  using  for  a  short  period  it  gradually 
loses  its  power,  but  if  left  to  rest  a  short 
time  it  recuperates  again.  After  running 

40 


down  a  number  of  times  it  begins  to  lose 
its  life,  and  the  full  power  is  not  derived 
after  recuperation. 

Soda  batteries  are  now  also  'extensively 
used,  and  appear  to  give  universal  satisfac- 
tion for  marine  engine  ignition,  generally 
requiring  but  one  charge  in  a  season.  The 
mlake-up  of  this  type  consists  of  a  porcelain 
or  enamel  steel  jar,  a  zinc  element,  a  cop- 
per oxide  element,  a  solution  of  soda  and 
a  heavy  oil.  The  oil,  although  playing  no 
part  in  the  chemical  action  of  the  elements, 
is  a  very  essential  part.  It  prevents  creep- 
ing of  salts  to  the  outside  of  the  jar,  and 
prevents  evaporation. 

This  type  of  battery  gives  between  .07 
and  .095  volts  for  ignition  purposes.  One 
valuable  point  of  superiority  is  that  it  has 
no  local  action ;  that  is,  the  elements  are 
not  consumed  while  not  in  use.  The  am- 
perage of  this  type  varies  according  to  size 
from  50  to  300. 

In  mixing  the  soda  solution  care  should 
be  exercised  not  to  get  any  of  the  liquid  on 
the  skin  or  clothes,  as  it  is  a  form  of  acid 
and  will  burn.  Very  little  attention  is 
necessary  after  setting  up,  and  when  run 


down  or  exhausted  the  state  of  the  elements 
can  be  easily  determined  as  to  whether  they 
are  in  condition  for  another  charge.  Usually 
they  will  permit  charging  a  second  time, 
buit  if  the  zincs  are  thin  they  should  be  dis- 


FiB    19 

carded,  as  it  is  poor  economy  to  use  an  in- 
efficient article. 

To  determine  the  condition  of  the  cop- 
per oxide,  pick  into  the  plate  with  a  knife 
or  sharp  instrument,  and  if  there  is  a  layer 


42 


of  black  in  the  interior  of  at  least  half  the 
thickness  of  the  plate,  it  will  give  good 
service  for  another  charge.  If  the  plate  is 
red  throughout,  it  is  entirely  exhausted  and 
is  useless.  Oxide  plates  should  never  be 
allowed  to  dry  outside  of  the  solution,  as 
the  result  expected  after  replacing  will  not 
be  realized  on  account  of  artificial  oxida- 
tion in  the  air. 

When  connecting  up  a  set  of  primary  bat- 
teries, the  zinc  of  one  battery  is  connected 
to  the  carbon  of  the  next  until  the  desired 
number  is  in  circuit.  If  batteries  are  to  be 
used  the  n-umjber  of  batteries  multiplied  by 
the  voltage  of  one  battery,  or  cell,  should 
equal  the  voltage  the  coil  is  intended  to 
work  on,  or  a  fraction  of  a  volt  more,  gen- 
erally 4  volts  for  jump  spark  coils  and  from 
6  to  8  volts  for  a  make-and-break  primary 
coil.  Either  7  or  8  soda  batteries  are  al- 
ways enough  for  the  latter  system, 

More  dry  batteries  are  generally  used 
than  figuring  the  same,  voltage  of  the  coil, 
on  account  of  the  batteries  getting  weaker 
during  use;  5  or  6  are  generally  used  for 
jump  spark  coils  and  8  for  make-and- 
break  system. 

43 


Two  sets  are  often  used,  connected  to  a 
two-point  switch,  so  that  either  set  can  be 
used.  In  case  one  set  gets  weak  the  other 
set  can  be  switched  on,  and  permit  the  used 
set  to  recuperate. 


Although    the   two    sets    as   above    de- 
scribed may  be  used,  if  the  batteries  were 


Fig.  21 

connected  as  shown  in  Fig.  20,  more  service 
could  be  derived  than  if  each  set  is  used 
separately,  as  shown  in-  Fig.  21.  As  pe- 


44 


culiar  as  it  may  seem,  by  actual  test  12 
batteries  of  15  amperes,  connected  as  shown 
in  Figure  20,  will  give  longer  service  than 
a  set  of  6  batteries  of  30  amperes',  or  than 
the  12  connected  in  two  sets  as  shown  in 
Figure  21.  This  result  is  slightly  adverse 
to  electrical  mathematics,  but  can  be  proved 
with  the  proper  apparatus. 

SECONDARY    BATTERIES. 

Secondary  batteries  are  commonly  called 
storage  batteries,  or  accumulators.  The 
make-up  of  this1  type  consists  of  a  hard 
rubber  or  non-breakable  jar,  lead  plates  and 
a  solution  of  diluted  sulphuric  acid.  The 
plates  of  the  positive  side  are  connected  to 
one  binding  post  or  lug,  and  the  negative 
plates  to  another  lug,  the  plates  being  sepa- 
rated in  the  solution  by  a  very  thin  piece 
of  corrugated  hard  rubber. 

After  charging,  the  positive  plates  are  of 
a  brown  color,  and  the  negative  plates  of  a 
gray  color.  The  reason  of  this  is.  because 
in  their  construction  the  positive  plate  only 
is  covered  with  peroxide  of  lead,  and  dur- 
ing discharge  causes  the  pure  lead  (nega- 
tive) plate  to  partially  oxidize  through  the 

45 


chemical  action  from  the  positive  plate. 

In  connecting  up  two  or  more  accumu- 
lators one  lug  of  each  battery  will  be  found 
to  be  marked  with  a  +  for  positive  and  a 
—  for  negative.  The  positive  of  one  bat- 
tery is  therefore  connected  to  the  negative 
of  the  next,  until  the  number  required  is 
in  circuit.  From  2  to  4  are  generally  re- 
quired for  ignition  purposes^  dependent 
upon  the  system  used.  A  storage  battery 
of  course  has  to  be  charged  from  some 
source  of  electricity,  consequently  a  dyna- 
mo is  utilized  for  this  purpose,  which  gives 
a  voltage  in  excess  of  the  voltage  of  the  set 
when  charged.  Each  storage  battery  gives 
from  2  to  2.y2  volts  and  amperage  consist- 
ent with  size  and  weight  of  plates. 

Storage  batteries  should  be  kept  clean, 
and  to  reach  this  end  the  portable  enclosed 
type  is  mostly  in  use.  If  any  acid  acci- 
dentally spills  or  evaporates,  a  solution  of 
very  weak  sulphuric  acid  should  be  added 
to  bring  the  liquid  to  a  proper  level  and 
test. 


46 


CHAPTER  V. 

DYNAMOS GENERATORS. 

A  dynamo  is  a  generator  of  electric  cur- 
rent, and  requires  a  power  to  rotate  its 
armature.  The  essentials  of  a  dynamo  are 
a  rotating  member  called  an  armature,  elec- 
tro magnets  called  fields,  an  armature  wind- 
ing of  insulated  copper  wire,  a  field  winding 
of  the  same  material,  a  commutator  and 
brushes.  The  principle  involved  in  produc- 
ing an  electric  current  from  a  generator  is 
the  rapid  revolving  of  a  number  of  turns  of 
copper  wire,  called  an  armature,  between 
the  magnetic  fields  or  poles  of  a  magnet. 
The  poles  of  a  magnet,  as  before  referred 
to,  are  the  ends  of  a  magnet,  either  electro 
or  permanent. 

A  dynamo  has  a  positive  and  negative 
wire ;  that  is,  the  current  from  this  type  has 
a  direction  of  flow  the  same  as  an  electric 
battery.  By  having  a  direction  of  flow  it  is 
called  direct  current,  and  this  current  can 
be  used  to  store  accumulators,  furnish  cur- 


47 


rent  for  jump  spark  coils,  either  vibrating 
or  non-vibrating,  or  make-and-break  spark 
coils. 

Figure  22  gives  an  outline  of  the 


Fiff.  22 

pie  of  the  type  of  generator  used  for  gas 
engine  purposes. 

A  A,  field  cores,  constructed  of  iron,  over 
which  field  wire  is  wound  ;  B  B,  brushes 
resting  on  commutator;  C,  the  armature; 
D  D,  the  line  wires. 


48 


As  shown  in  Figure  23,  the  commutator 
is  made  up  of  a  number  of  segments  of 
brass  or  copper,  forming  a  circle,  each  seg- 
ment separated  from  its  neighbor  by  either 
mica  or  hard  rubber  insulation,  and  is  set 
on  the  end  of  the  armature  shaft.  Each 
end  of  each  winding  of  wire  on  the  arma- 


Fig.  23 

ture  is  soldered  to  its  respective  segment 
on  the  commutator,  and  the  current  gen- 
erated is  taken  from  the  commutator 
through  the  brushes  as  the  armature  re- 
volves. 

A,  commutator;  B,  armature  winding;  C, 
armature  shaft. 

By  both  wires  leading  from  the  fields  be- 
ing connected  to  each  brush,  part  of  the 
current  generated  by  the  armature  goes 


49 


Improved  Speed  Regulating:  Dynamo. 


50 


through  the  fields  to  magnetize  the  field 
cores  and  make  magnetic  poles  for  the  arm- 
ature to  revolve  upon. 

MAGNETOS. 

A  magneto  is  also  a  generator  of  elec- 
tricity, but  instead  of  having  wire  wound 
on  the  field  cores,  utilizes  what  is  known 
as  permanent  magnets  of  the  horseshoe 
type.  This  gives  a  permanent  magnetic 
field  for  the  armature  to  revolve  in. 

There  are  several  different  types  of  this 
machine,  and  they  vary  in  construction  to 
produce  practically  the  same  result,  al- 
though the  principle  is  the  same.  For  ig- 
nition purposes  one  type  produces  alter- 
nating current  of  from  8  to  10  volts,  an- 
other direct  current  of  the  same  voltage  and 
another  furnishes  a  high  voltage  in  connec- 
tion, with  a  coil  made  and  placed  within  the 
magneto  case. 

The  direct  current  magneto,  although 
having  an  output  of  about  10  volts,  has  a 
very  low  capacity  of  less  than  one  ampere. 
Its  principle  of  operation  is  similar  to  that 
of  the  ignition  dynamo.  It  can  be  utilized 


51 


to  furnish  current  to  a  make-and-break 
spark  coil  or  the  magnetic  primary  plug, 
but  is  not  adapted  for  furnishing  current 
to  a  jump  spark  coil  direct,  owing  to  its 
low  output  of  amperage.  The  only  means 
of  utilizing  it  for  this  kind  of  ignition  is 
through  the  medium  of  a  storage  battery 
set,  for  the  following  reason :  While  a  stor- 
age battery  or  accumulator  set  furnishes  the 
proper  amount  of  amperes  to  operate  a 
jump  spark  coil,  the  drain  therefrom  is 
only  intermittent;  that  is,  there  is  more 
actual  space  or  time  between  connection 
through  the  timer  on  the  engine  than  there 
is  in  contact.  As  the  direct  current  mag- 
neto furnishes  a  smaller  amount  of  amperes 
than  is  used  from  the  accumulators,  the 
supply  is  constant,  and  enables  the  batteries 
to  be  kept  fully  stored. 

By  using  the  accumulators  in  connection 
with  a  direct  current  magneto,  either  vi- 
brating or  non-vibrating  coils  can  be  used. 

The  alternating  current  magneto  is  very 
much  like  the  direct  current  magneto  in 
appearance,  and  is  used  more  extensively 
for  mechanical  make-and-break  ignition 
spark  coils.  The  difference  between  the 


52 


two  types  of  magneto,  is  only  in  the  man- 
ner in  which  the  armature  winding  is  ar- 
ranged. In  the  alternating  current  mag- 
neto there  is  no  direction  of  flow  of  the 


current  produced.  It  alternates  from  one 
binding  post  or  brush  to  the  other  many 
thousand  times  in  a  minute. 


53 


Alternating  current  is  therefore  unlike  a 
direct  or  battery  current,  because  it  has  no 
positive  or  negative  wire.  It  will  not  ring 
an  ordinary  electric  bell  or  magnetize  an 
electro  magnet.  For  make-and-break  ig- 
nition, magnetism  is  not  utilized  for  the 
operation  of  this  system,  other  than  for  the 
type  of  magnetic  primary  igniters  before 
mentioned.  When  used  in  conjunction  with 
a  make-and-break  spark  coil,  very  good  re- 
sults have  been  given. 

This  form  of  magneto  has  also  been  util- 
ized to  some  extent  with  jump  spark  coils 
without  a  vibrator,  the  alternations  pro- 
ducing a  series  of  sparks  as  the  circuit  is 
closed  by  the  engine  timer,  corresponding 
to  the  action  of  a  jump  spark  coil  with 
vibrator,  when  used  with  battery  or  dy- 
namo. An  alternating  current  magneto  will 
not  operate  a  vibrating  jump  spark  coil  be- 
cause the  core  requires  to  be  magnetized 
on  the  same  principle  as  an  electro  magnet, 
to  attract  the  vibrator  of  the  coil.  Mag- 
netic primary  igniters  will  not  operate  with 
alternating  current  for  the  same  reason. 

High   tension  or   voltage   magnetos,  are 
now  manufactured  which  require  no  out- 


54 


side  coil,  and  are  operated  through  the  ordi- 
nary jump  spark  plug. 

The  magn-eto  is  so  well  known  in  appear- 
ance that  a  further  description  is  not  neces- 
sary. 

Magnetos  are  now  made  without  what 
appear  to  be  brushes.  One  side  of  the  cur- 
rent from  the  armature  coil  is  grounded  in 
the  armature,  and  the  magneto  frame  me- 
tallically connected  to  the  engine  frame. 
The  other  wire  is  connected  to  a  sleeve 
around  the  shaft  or  to  the  shaft  itself,  which 
is  insulated  from  the  armature,  the  shaft  or 
sleeve  pressing  against  a  spring,  the  end  of 
which  is  made  fast  to  a  binding  post  insu- 
lated from  the  magneto  frame.  This  meth- 
od gives  the  appearance  of  no  brushes  to 
the  magneto,  but  one  is  theoretically  there. 

The  one  wire  leading  from  the  insulated 
binding  post  is  connected  to  the  spark  coil 
binding  post,  and  another  wire  from  the 
coil  to  a  switch,  thence  to  the  insulated  plug 
of  the  engin-e,  where,  upon  contact,  the  cur- 
rent flows  through  the  engine  frame,  re- 
turning to  the  magneto  and  armature  wind- 
ing. 


55 


CHAPTER  VI. 

TESTING    FOR   TROUBLE. 

One  of  the  principal  causes  of  trouble 
in  the  electrical  equipment  of  a  marine  gaso- 
line engine,  especially  when,  used  on  salt 
water,  is  the  corrosion  of  copper  wires, 
caused  by  being  in  close  proximity  to  met- 
als of  opposite  polarity,  both  of  which  -may 
be  situated  in  a  damp  place,  either  in  the 
bilge  of  the  boat  or  where  continual  spray 
is  thrown  when  under  way. 

A  broken  wire  is  a  very  perplexing  prob- 
lem to  locate  to  the  novice.  If  a  broken 
wire  is  suspected  between  one  battery  and 
another,  it  can  be  easily  proved  or  located 
by  connecting  a  piece  of  wire  to  the  zinc 
binding  post  at  the  end  of  the  set  and  rub- 
bing the  other  end  of  the  wire  on  the  car- 
bon plate  on  the  battery  at  the  other  end 
of  the  set,  but  not  on  the  binding  post.  If 
the  connections  between  each  battery  are  all 
right,  a  small  arc  or  flame  will  occur  be- 
tween the  wire  and  the  carbon  each  time 


56 


they  come  in  contact,  but  if  an  open  circuit 
prevails,  or  the  batteries  have  become  ex- 
hausted, no  spark  will  appear. 

Before  placing  the  wire  on  the  zinc  bind- 
ing post,  remove  the  permanent  wire  there- 
from and  open  the  switch,  so  that  there 
can  be  no  ground  at  any  point  in  the  outside 
wires,  and  through  the  battery  box  in  any 
unforseen  manner.  By  going  over  each 
binding  post  very  often  a  loose  connection 
with  the  wires  and  binding  posts  will  be 
found  as  the  cause.  If  the  binding  posts 
are  making  a  good  connection,  with  the  piece 
of  wire  still  fastened  at  the  zinc  binding 
post,  making  a  perfect  metallic  connection, 
touch  the  carbon  of  the  battery  next  near- 
est the  end  where  the  zinc  and  wire  are 
connected  and  continue  thus  with  each  bat- 
tery toward  the  zinc  connection  until  a 
spark  is  seen  on  the  carbon.  As  soon  a'b 
it  sparks,  the  trouble  is  between  that  bat- 
tery and  the  one  next  to  it  which  would  not 
spark. 

Should  the  batteries  appear  to  be  in  per- 
fect condition,  and  in  case  the  engine  should 
fail  to  start,  if  the  equipment  is  make-and- 
break  system  of  ignition,  remove  the  wire 

57 


from  the  insulated  electrode  or  plug  and 
wipe  it  across  any  bright  or  polished  part 
of  the  engine,  after  closing  the  switch. 

If  a  spark  occurs,  following  the  wire 
each  time,  turn  over  the  fly  wheel  until 
contact  is  iniade  by  the  movable  and  station- 
ary electrode  inside  of  the  cylinder.  This 
point  occurs  just  before  the  device  on  the 
outside  of  the  cylinder  trips  or  snaps,  which 
separates  the  electrodes.  Now,  wipe  the 
wire  across  the  insulated  plug  electrode, 
and  if  a  spark  occurs,  turn  the  fly  wheel 
still  further  until  the  device  snaps  to  sepa- 
rate the  electrodes,  and  try  the  same  thing 
again.  If  no  flame  is  perceptible,  the  spark 
is  occurring  inside  of  the  cylinder.  The 
trip  separating  the  electrodes  should  occur 
barely  before  the  piston  reaches  its  top  cen- 
ter, generally  marked  by  a  cut  in  the  fly- 
wheel rim  to  alleviate  matters. 

A  puzzling  stage  to  many  is  when,  after 
all  these  tests,  no  spark  has  shown  itself, 
and  the  batteries  are  all  right.  The  trouble 
may  be  a  broken  wire,  bad  connection  at 
switch  connections  or  contacts,  switch  bind- 
ing posts,  coil  binding  posts  or  ground  bind- 
ing posts  on  the  engine  frame.  Referring 


58 


to  Figure  26,  a  make-and-break  system  of 
connection  is  shown. 

Proceed  to  locate  the  trouble  by  turning 
the  engine  fly  wheel  so  as  to  make  connec- 
tion between  the  electrodes.  See  that  the 


Fig.  26 

switch  is  closed,  and  with  a  piece  of  wire, 
place  one  end  at  G  on  the  batteries  and 
wipe  the  other  end  across  the  top  of  the 
insulated  electrode  or  plug,  A.  If  a  spark 
shows,  the  trouble  is  either  in  the  ground 
wire,  where  it  is  connected  to  the  battery, 


59 


or  the  engine  frame,  or  between  the  two 
electrodes  possibly  by  a  bad  connection,  of 
sparking  points. 

If  no  spark  appears,  with  one  end  still 
at  G,  repeat  the  same  operation  at  the  coil 
binding  post,  E.  If  a  spark  appears,  the 
trouble  is  either  at  binding  post  E,  or  in 
the  wire,  or  at  A,  on  the  insulated  electrode. 
If  no  spark  shows  itself,  trouble  is  either 
at  D  of  coil,  C  or  B  of  the  switch  or  battery 
connection,  F,  or  'poor  connection  in  the 
knife  switch  or  contact. 

The  next  mode  of  procedure  will  be  to 
fasten  the  temporary  wire  at  battery  con- 
nection F,  and  touch  other  end  of  wire  to 
binding  post  B,  on  the  switch,  first  of  all 
trying  switch  points  by  sand-papering  and 
noting  if  spark  follows  points  when  open- 
ing switch.  With  the  supposition  that  an 
open  circuit  still  prevails',  by  no  spark  show- 
ing when  touching  temporary  wire  to  B, 
touch  next  to  C  of  switch,  and  then  to  D. 
When  a  spark  is  noticed  the  trouble  lies 
between  where  spark  occurred  and  the  last 
point  it  failed  to  show. 

There  may  be  such  a  thing  that  after  a 
period  unused  the  whole  installation  may 


be  defective.  If  no  spark  can  be  deter- 
mined at  all,  this  can  be  ascertained 
by  fastening  temporary  wire  at  F  and  D, 
and  with  another  piece  of  wire,  fastened  to 
G,  touch  the  binding  post  E,  of  the  coil.  A 
spark  should  now  show  itself,  as  this  cuts 
out  the  engine  and  switch  and  all  the  wir- 
ing, and  should  be  convincing  enough  to 
show  the  necessity  for  new  wires. 

Although  appearing  to  be  a  rather  in- 
tricate mtethod,  any  person  can  soon  learn 
the  why  and  wherefore. 

For  jump  spark  ignition  remove  the  plug 
from  the  cylinder  and  lay  it  on  a  bright 
metallic  part  of  the  engine,  with  the  wire 
attached  to  it,  being  sure  that  only  the  por- 
tion of  the  side  metal  containing  the  screw 
threads  make  the  connection,  the  sarnie  as 
if  screwed  into  the  cylinder.  Turn  over 
the  engine  until  contact  is  made  at  the  timer 
or  commutator.  If  the  trembler  or  vibrator 
of  the  coil  does  not  operate,  adjust  by  turn- 
ing the  thumb  screw  in  either  direction  until 
it  does.  If  it  fails,  pass  a  fine  piece  of  sand 
paper  between  the  point  on  the  trembler 
and  the  thumb  screw  adjuster.  If  it  op- 
erates now,  observe  the  size  of  spark  at  the 
spark  plug. 

61 


Jump  spark  coils  are  invariably  situated 
near  the  engine  and  batteries,  and  are  very 
convenient  for  locating  trouble.  If  a  good- 
sized  wire  is  used  when  installing,  a  failure 
of  the  vibrator  to  work  can  be  located  by 
seeing  that"  good  contact  is  made  at  timer, 
switch  points  are  clean,  binding  posts  tight ; 
in  the  event  of  which  all  are  in  good  con- 
dition, the  same  test  for  trouble  in  the  bat- 
teries as  before  mentioned  can  be  used. 
When  batteries  are  suspected  of  causing  the 
trouble,  new  batteries  are  not  always  at 
hand  to  put  in  their  place  to  save  testing 
out. 

With  jumip  spark  ignition,  very  often 
after  putting  in  new  batteries,  a  very  hot 
spark  occurs  at  the  vibrator  and  a  weak 
spark  at  the  plug.  This  is  caused  by  a 
poor  connection  between  the  condenser  and 
the  wires  leading  to  the  vibrator  inside  of 
the  coil  case.  The  best  thing  to  do  in  this 
case  is  to  send  the  coil  to  the  manufac- 
turer or  discard  it,  unless  the  operator  has 
the  ingenuity  to  repair  it  and  understands 
its  principle  and  theory. 


62 


INSTALLATION  OF  IGNITION  SYSTEM. 

Do  not  use  small  gauge  wires,  as  they 
are  too  readily  subjected  to  injury.  No.  14, 
and,  better  yet,  No.  12,  safety  wire  will 
carry  the  current  better  and  stand  harder 
usage.  Always  wind  several  turns  on  a 
pencil  before  fastening  an  end  to  a  binding 
post,  so  that,  should  a  break  occur  at  the 
fastening,  enough  will  be  left  for  another 
connection. 

If  imperative  to  run  wires  along  the  bilge 
in  a  damp  place,  use  lead-covered  wire. 
Run  all  wires  in  the  lockers  if  possible,  or 
under  the  edge  of  the  'coaming.  Never 
fasten  two  wires  under  one  staple,  or  a 
short  circuit  may  be  caused  by  cutting 
through  the  insulation  of  the  wires  and  each 
point  touching  the  metal.  Do  not  drive  sta- 
ples home,  as  they  are  liable  to  cut  the  in- 
sulation and  break  the  wire. 

Single  or  double  pole,  double  throw,  knife 
switches  for  two  sets  of  batteries  or  mag- 
neto and  battery,  or  single-throw  knife 
switches,  or  electric  light  snap  switches, 
give  better  results  than  the  ordinary  elec- 
tric bell  or  automobile  switch,  for  the  rea- 


63 


son  that  the  former  have  a  rub  pressure 
contact  attendant  with  closing. 

When  installing  a  double-throw  knife 
switch,  set  it  up  horizontally,  so  that  it  will 
not  close  by  its  own  gravity.  Single-throw 
switches  should  be  set  up  vertically,  so  that 
in  opening,  the  lever  is  pulled,  down,  for 
the  same  reason. 

Place  all  dry  batteries  in  a  dry  place.  If 
the  whole  set  is  not  sealed  up  in  pitch,  and 
if  inconvenient  to 'procure  any,  connect  the 
set  together,  soldering  all  connections,  and 
place  them  in  a  box  to  just  nicely  contain 
them.  Put  binding  posts  on  the  end  of  the 
box  or  extend  the  wires:  through  the  holes 
in  the  box,  and  fill  the  case  with  pitch  or  as- 
phalt. This  will  keep  the  set  water-proof 
under  all  circumstarces.  Those  who  desire 
to  keep  dry  batteries  from  absorbing  mois- 
ture, and  do  not  care  to  use  pitch,  can  place 
the  set  in  a  box,  filling  same  to  the  top  with 
sawdust.  When  this  absorbing  material  be- 
comes damp,  renew. 

All  dry  batteries  should  be  set  right  side 
up,  unless  water-proofed  with  pitch,  else 
the  pitch  in  the  top  of  the  cans  will  run  on 


warm  days  and  permit  the  contents  to  evap- 
orate. 

When,  putting  screws  or  nails  in  a  battery 
box  to  hold  it  in  position,  be  sure  to  see 
that  a  nail  or  screw  has  not  misdirected  and 
touches  one  of  the  batteries  and  a  wire. 

Brighten  all  contacts  and  ends  of  wires 
when  fastening  to  binding  posts,  screws, 
etc.,  and  solder  and  tape  over  any  splice 
made  in  the  wire. 

When  the  novice  installs  his  own  jump- 
spark  electrical  equipment,  it  is  a  common 
occurrence  to  find  ordinary  electric  light 
wire  leading  from  the  coil  to  the  spark  plug 
on  the  engine.  Very  few  explosions  are 
gotten  from  the  engine  before  trouble  oc- 
curs. Notwithstanding  the  use  of  ordinary 
wire  when  there  is  more  than  one  cylinder 
to  the  engine,  these  wires  are  bunched  to- 
gether and  taped. 

Rerr;ember  that  it  is  most  imperative  that 
wire  with  a  heavy  insulation  of  rubber  is 
necessary  for  this  secondary  current  to 
carry  to  the  plug,  on  account  of  the  high 
voltage  and  liability  to  jump  through  the 
insulation  of  ordinary  wire.  If  unable  to 
procure  the  heavy  insulated  wire,  use  the 


65 


66 


ordinary  wire,  but  procure  a  piece  of  pure 
rubber  tube  or  circular  loom,  such  as  elec- 
tric light  wires  are  run  through,  and  slide 
this  over  the  wires. 

Wire  terminals  are  now  manufactured 
which  facilitate  a  good  metallic  connection, 
and  also  prevent  the  wire  from  breaking 
at  the  point  of  connection.  Figure  27  shows 
two  forms  of  spark  plug  wire  connectors, 
A  and  B,  and  a  form  of  battery  terminals,  C. 

Water-proof  plug  protectors  are  being 
utilized  to  great  advantage  in  protecting 
the  plug  and  wire  terminal  from  corrosion 
and  short  circuits  caused  by  spray.  These 
are  a  boon  to  the  open  power  boat. 


67 


CHAPTER  VII. 

KINKS  IN  THE  POWER  INSTALLATION. 

Difficulties  are  encountered  other  than  in 
the  ignition  system  of  a  marine  engine. 
Poor  water  circulation  or  chronic  trouble  in 
starting  the  water  flow  through  a  gear  or 
rotary  pump,  foreign  substances  in  the 
gasoline,  affecting  carburation,  trim  or  mo- 
tion of  the  boat  acting  on  the  gasoline  level 
in  the  fuel  tank,  leaks  in  the  gasoline  pipe 
or  connections,  sticking  of  the  check  valves 
in  the  water  supply,  etc.,  are  troubles  very 
often  traced  directly  to  the  manner  in  which 
installation  was  put  in. 

Unless  a  rotary  or  gear  pump  is  placed 
at  a  point  below  the  water  line  in  a  boat, 
there  is  no  suction  to  start  the  water  to 
flow,  and  priming  with  water  has  to  be  re- 
sorted to,  and,  even  though  they  work  sat- 
isfactorily when  new,  they  soon  require  the 
primting  process,  as  all  the  water  escapes 
from  the  cylinder  jacket  through  the  pump 
when  not  in  operation.  The  best  remedy 


for  this  is  to  place  a  check  valve  between 
pump  and  entrance  of  pipe  through  the 
hull.  This  will  insure  the  pump  remaining 
rilled  with  water,  by  the  check  closing  when 
the  pump  stops  and  remaining  wide  open 
while  running. 

SUPPLY  PIPE 


TO 
VAPORIZER 


FASTEN  PET  COCK 

Fie    28 

Any  foreign  matter  in-  the  fuel  can  be 
readily  drained  from  the  pipe  by  the  use  of 
a  T  connection  with  a  sight  glass  fitted  with 
a  pet  cock  at  its  lowest  point,  as  shown  in 
Figure  28. 


Water  is  the  most  annoying  substance  in 
the  fuel,  but  with  this  form  of  filter  or  sepa- 
rator, its  presence  can  be  detected,  as  well 
as  any  sediment,  etc.,  as  it  will  settle  to 
the  bottom  of  the  gasoline  by  its  own  grav- 
ity. The  gasoline  enters  the  tip,  going  out 
the  side  of  the  T  to  the  vaporizer.  Sedi- 
ment in  the  gasoline  pipe  is  often  traced  to 
the  use  of  a  galvanized  iron  tank.  An- 
nealed copper  tanks,  tinned  inside,  are  the 
most  satisfactory  and  only  safe  tank  to  in- 
stall in  a  boat.  No  matter  what  the  tank 
is  constructed  of,  it  should  rest  in  a  pan, 
fitted  with  outboard  scuppers  and  separated 
from  the  boat  proper  by  a  bulk-head,  mate- 
ing  an  air-tight  comtpartment. 

In  case  of  leaks  developing  in  the  tank, 
the  contents  will  run  into  the  pan  and  be 
directed  outboard,  and  not  enter  the  hull,  to 
cause  fire. 

Leaks  in  the  gasoline  tank  are  very  dan- 
gerous, and  should  be  repaired  at  once.  The 
pipe  should  be  in  one  piece,  either  lead  01 
annealed  copper,  and  all  connections  made 
fast  with  soft  solder.  When  setting  up 
threaded  ends  of  gasoline  pipe,  they  should 
be  sweated  in  or  set  up  with  brown  shellac, 


70 


and  nothing  else.  Gasoline  often  escapes 
from  the  vaporizer  or  carbureter  and 
lodges  in  the  bilge  of  the  boat,  endangering 
a  fire.  The  only  safe  method  in  such  in- 
stances is  to  arrange  a  pan,  or  length  ot 
pipe  like  a  U,  under  the  vaporizer. 

The  motion  or  roll  of  the  boat  may  cause 
the  mouth  of  the  gasoline  pipe  in  the  tank 
to  occasionally  be  uncovered.  Cylindrical 
and  V-shaped  tanks  overcome  this  difficul- 
ty. When  equipped  with  a  square  tank, 
and  trouble  of  this  sort  prevails,  arrange 
the  piping  as  shown  in  Figure  29,  with  an 
outlet  from  both  sides. 

Check  valves  in  the  water  inlet  pipe  often 
placed  near  the  cylinder  jacket,  cause  an- 
noyance by  rust  backing  up  to  the  check, 
forming  a  deposit  on  the  valve  seat,  affect- 
ing the  water  circulation.  Checks  should 
always  be  kept  clean,  and  occasionally 
smeared  with  vaseline  or  oil  on  the  seat. 

When  a  new  engine  has  been  installed 
by  a  novice,  very  often  the  engine  will  stop 
after  a  few  minutes'  run>,  with  apparently 
no  reason  for  doing  so,  and  after  a  thorough 
examination  of  every  part  shows  nothing 
amiss.  The  cause  of  this  is  often  due  to 


71 


the  absence  of  a  vent  in  the  gasoline  tank, 
which  can  be  remedied  in  a  small  equip- 
ment by  drilling  or  punching  a  very  small 
hole  in  the  rilling  cap  of  the  tank.  In  larger 
equipments  it  is  better  to  solder  a  ^-inch 
copper  pipe  to  the  top  of  the  tank,  leading 


same  to  a  point  well  toward  or  at  the  stern, 
over  deck. 

One  of  the  safest  methods  of  installing 
a  gasoline  tank  in  a  power  boat  is  to  insert 
a  brass  pipe  in  'the  top  of  the  tank,  of  suffi  • 
cient  size  to  be  convenient  for  filling,  set 
up  on  the  inside  and  outside  of  the  tank 


72 


with  lock  nuts,  soldered  fast.  The  top  of 
the  brass  pipe  should  be  long  enough  to  ex- 
tend through  the  deck  far  enough  for  a  col- 
lar to  screw  on  and  fasten  to  the  deck,  and  a 
cap  to  cover  the  open  end  and  set  up  against 
the  collar.  In  the  event  of  any  gasoline 
spilling  during  the  fitting  of  the  tank,  it  can 
not  enter  the  boat,  and  must  go  overboard. 

Never  place  any  rubber  gaskets,  hose, 
etc.,  in  connection  with  any  pipe,  part  of 
the  tank,  carbureter,  etc.,  where  either 
gasoline  or  its  vapor  is  liable  to  come  in 
contact  with  same.  Rubber  is  soluble  in 
gasoline,  and  may  cause  a  disastrous  leak 
at  any  time  if  used. 

Never  place  a  stop  cock  in  the  water 
overflow  pipe  leading  from  engine  outboard 
or  into  exhaust  pipe.  It  will  sooner  or  later 
be  found  closed,  after  the  pump  has  broken 
or  the  water  jacket  cracked. 


73 


CHAPTER  VIII. 

HORSEPOWER.  • 

One  of  the  most  peculiar  phases  con- 
fronting the  intending  purchaser  of  a  ma- 
rine engine  is  how  to  estimate  the  horse- 
power of  any  engine  under  consideration. 
The  suspicion  of  overrating  invariably  pre- 
sents itself,  especially  when  two  styles  of 
different  speed,  weight  and  size  claim  the 
same  power. 

Irrespective  of  manufacturer's  rating,  the 
feeling  exists  to  know  the  exact  rating  and 
what  a  horsepower  constitutes. 

An  American  or  English  horsepower 
represents  the  equivalent  of  33,000  pounds 
raised  to  a  height  of  I  foot  during  a  period 
of  i  minute,  or  1,000  pounds  33  feet  in  i 
minute,  or  550  pounds  per  second,  or  any 
proportional  combination  of  these  figures. 
This  represents  the  value  of  an  American 
or  English  horsepower,  and  not  a  French 
horsepower. 

The  French  people  utilize  two  kinds  of 
horsepower,  cheval  vapeur  and  poncelet. 


The  former  is  the  value  of  32,550  pounds 
raised  I  foot  in  I  minute,  or  542.5  pounds 
per  second,  which  is  .9863  that  of  the  Eng- 
lish horsepower.  Poncelet  equals  the  value 
of  43,400  pounds  raised  I  foot  in  I  minute, 
or  1-3  more  than  cheval  vapeur.  Poncelet 
is  used  for  laboratory  tests,  while  internal 
combustion  engines  are  rated  by  the  cheval 
vapeur. 

In  French  measurements  the  English 
horsepower  represents  76.04  kilogram 
meters  per  second;  cheval  vapeur,  75  kilo- 
gram meters  per  second,  and  poncelet,  100 
kilogram  meters  per  second.  It  will  thus 
be  seen  that  there  is  a  difference  of  about 
2  per  cent  between  the  horsepower  of  a 
French  engine  and  one  of  Amrican  manu- 
facture. An  American  engine  would,  there- 
fore, figure  less  power,  dimensions  for  di- 
mensions, than  one  of  French  manufac- 
ture. 

It  must  be  taken,  into  consideration  that 
different  compression  space  dimensions,  de- 
sign, workmanship  and  material,  may  be 
the  cause  of  different  power  ratings  for  the 
same  dimensions  and  speed.  There  are  sev- 
eral rules  for  approximately  figuring  the 


75 


horsepower  of  an  internal  combustion  en- 
gine. 


AMERICAN    POWER   BOAT   ASSOCIATION    RULE. 

Area  of  piston,  multiplied  by  the  num- 
ber of  cylinders,  times  the  revolutions  per 
minute,  divided  by  1,000  for  a  4-cycle  and 
750  for  a  2-cycle  engine. 

Designated  by  : 

D2  X  .7854  X  N   X  R 

-  =H  P.  4-cycle. 

IOOO 

D2  x  .7854  x  N  x  R 
----  .  =  H.  P.  2-ccle. 


D  equals  diameter,  N  equals  number  of 
cylinder,  R  equals  revolutions  per  minute. 

A  rule  used  by  several  manufacturers  is 
to  square  the  diameter  of  the  cylinder,  mul- 
tiply by  the  stroke,  then  by  the  revolutions 
per  minute,  and  number  of  cylinders,  divid- 
ing this  result  by  17,000  for  a  4-cycle  and 
by  13,000  for  a  2-cycle  engine. 


76 


D2x  LX  R  XN' 

-  =H  P.  4-cycle. 


17,000 


=  H.  P.  2-cycle. 


13,000 


D  equals  diameter  piston,  L  equals  length 
stroke,  R  equals  revolutions  per  minute,  N 
equals  number  of  cylinders. 

Another  rule  is  to  figure  10  cubic  inches 
piston  displacement  per  horsepower  for 
high-speed  4-cycle  engines,  and  8  cubic 
inches  for  a  high-speed  2-cycle. 

Which  is : 

D2  X  .7854  X  L  X  N 

=  H.  P.  4-cycle. 

10 

D2x  .7854 XL 


=  H.  P.  2-cycle. 


8 


The  rule  for  high-speed  engines  refers 
to  those  rated  at  from  950  to  1,500  revolu- 
tions per  minute. 


77. 


This  high  speed  is  not  utilized  to  any  ad- 
vantage over  1,000  revolutions  per  minute 
in  a  power  boat,  and  if  a  speed  of  800  to 
900  is  realized  it  can  be  more  practically 
utilized. 

If  the  engine  is  rated  at  1, 600  revolu- 
tions, the  power  development  will  be  about 
one-half  at  800,  and  if  rated  at  1,200  revo- 
lutions, two-thirds  the  power  derivation 
will  be  realized  at  800. 

By  noting  the  American  Power  Boat  As- 
sociation's rating  of  various  engines  in 
comparison,  to  the  manufacturers'  rating, 
and  especially  those  of  foreign  rating,  a  dif- 
ference will  be  noticeable. 

On  account  of  the  demand  created  by  the 
high  speed  development  of  the  a'utomobile, 
high-speed  marine  engines  are  in  demand, 
notwithstanding  their  short  length  of  life. 
Unless  the  craft  is  strictly  a  speed  boat,  a 
lightly  constructed  engine  is  wholly  out  of 
place. 

The  following  tables  of  dimensions  are 
the  engine  ratings  of  prominent  manufac- 
turers. Various  sizes  of  engines  are  pro- 
duced by  multi-cylinder  of  2,  3,  4,  6  and  8 

78 


combinations.     The  horsepower    is    for    a 
single  cylinder  engine  in  the  following : 


2-cycle,   2-ported   type. 


H.P. 

R.P.M. 

Bore. 

Stroke. 

1/2 

500 

3/2     . 

3/2 

2 

500 

3tt 

4 

3/2 

550 

4/2 

5 

7/2 

•  425 

5/2 

6y2 

10 

350 

7 

7/2 

2-cycle,  3-ported  type. 
H.P.      R.P.M.      Bore.      Stoke.      Weight. 


I 

700 

3 

2/2 

38 

2 

950 

3 

3 

75 

3 

500 

4 

4 

150 

4 

900 

3/ 

35A 

125 

5 

600 

4/2 

5 

180 

79 


4-cycle. 


H.P. 

R.P.M. 

1   Bore. 

Stoke. 

i 

750 

2/2 

4 

2^ 

600 

3/2 

5 

3 

950 

3/4 

3/2 

3/2 

600 

4l/2 

5 

4 

900 

4 

4/4 

5 

500 

5 

6 

7 

800 

4tt 

5 

7/ 

450 

&A 

7 

7/2 

450 

6/4 

7 

8 

800 

5 

5 

10 

750 

5/2 

6 

15 

800 

6/ 

6^2 

80 


CHAPTER  IX. 

WIRING   DIAGRAMS. 

In  making  use  of  the  various  wiring 
diagrams  on  the  following  pages,  it  will 
be  well  to  remember  that  the  order  of  firing 
the  cylinders  in  a  multi-cylinder  engine  has 
not  been  set  forth.  This  order  of  firing, 
for  jump  spark  ignition,  in  a  four-cycle 
engine  can  be  located  by  the  positions  of 
the  cams  on  the  cam  shaft  for  the  exhaust 
valve  lifts.  Before  wiring  to  the  com- 
mutator or  timer,  the  fly  wheel  can  be 
turned  over  until  the  exhaust  valve  cam 
of  the  cylinder  nearest  the  front  of  the 
engine  starts  to  open  the  valve.  This  indi- 
cates that  this  same  cylinder  was  the  last 
to  ignite,  consequently  the  last  to  close  the 
primary  circuit  at  the  timer. 

By  locating  the  binding  post  on  the 
timer  which  is  then  the  one  just  passed 
contract,  with  the  timer  retarded  for  a  late 
spark,  in  other  words,  the  timter  cover  or 
case  carrying  the  binding  posts  or  connec- 


81 


tions,  moved  as  far  as  practical  in  -the 
same  direction  as  that  which  the  timer 
shaft  rotates.  When  this  binding  post  is 
located,  the  primary  wire  of  coil  number 
one  is  fastened  to  same,  and  the  secondary 
wire  of  coil  number  one  made  fast  to  the 
plug  on  cylinder  number  one.  The  flywheel 
can  then  be  turned  over  until  the  next  cam 
comes  into  action  for  locating  the  next  con- 
nection, or  can  be  found  by  looking  along 
the  cam  shaft  until  the  next  cam  to  come 
into  action  is  located  or  figured  out. 

Although  a  four-cylinder  engine  may 
fire,  i,  2,  4,  3,  the  secondary  wires  should 
be  led  to  the  plug  direct  without  crossing, 
as,  coil  i  to  cylinder,  i,  2  to  2,  3  to  3,  4  to  4, 
and  the  changes  for  order  of  firing  arranged 
at  the  timer  by  the  primary  connections 
thereto.  Each  primary  wire  from  the  coil 
to  the  timer,  is  for  the  secondary  or  plug 
wire  directly  over  the  formler  on  the  coil. 
Multi-cylinder  coils  are  made  up  of  single 
cylinder  coils. 

When  wiring  a  two-cycle  multi-cylinder 
engine,  the  order  of  firing  can  be  located 
by  noting  which  crank  revolves  next  in 
order  from  number  one  cvlinder. 


S2 


For  make-and-break  ignition,  the  spark- 
ing mechanism  on  the  outside  of  each 
cylinder  generally  takes  care  of  the  firing 
of  each  cylinder  correctly. 

Each  of  the  following  diagrams  is  ar- 
ranged for  two  sets  of  batteries,  to  use 
each  set  at  will,  through  the  medium  of  a 
two-point  or  double-throw  switch.  If  a 
generator  is  to  be  used,  with  one  set  of 
batteries  for  starting,  the  arrangement  is 
made  in  the  same  manner  in  the  circuit  as 
if  one  set  of  the  two  represented  in  the 
diagrams  was  removed,  and  the  generator 
inserted  in  its  place. 

The  diagram  key  is :  P.  plug,  S.  switch, 
T.  timer,  ==  ground. 


83 


Single   Cylinder.   2   Sets  Batteries.   Make-and 
Break. 


84 


n 


Two-Cylinder.  Make-and-Break.  2  Sets  Batteries. 


85 


Single-Cylinder.  3  Terminal  Coil.  2  Sets  Bat- 
teries. Jump  Spark. 


Single  Cylinder,   4   Terminal  Coil.   2   Sets  Bat- 
teries. Jump  Spark. 

87 


Single  Cylinder.  6  Terminal  Coil.  2  Sets  Bat- 
teries.   Jump   Spark. 


88 


Two-Cylinder.   5  Terminal  Coil.  2   Sets  Batteries. 
Jump  Spark. 


Three-Cylinder.  7  Terminal  Coil.  2  Sets  Batteries. 
Jump   Spark. 


,90 


Four-Cylinder.  9  Terminal  Coil.  2  Sets  Batteries, 
Jump  Spark. 


91 


INDEX. 


Page. 

Accumulators     45 

Advancing  S'park   13 

Alternating  Current   54 

Ampere    3 

Auxiliary   Spark   Gap 3 

Batteries    86 

Batteries,  Primary   36 

"          Storage    45 

Broken  Wire  Trouble 56 

Coil,  Jump  SparK   17 

Coil,  Jump  S'park.  Action  of 25 

Coil,  Jump  S'park,  Construction  of 22 

Coil,  Make-and-Break   9 

Coil,  Vibrating   25 

Commutators 32 

Condenser,  Electrical   19,  23 

( :onnecting  Primary  Batteries 43 

Connecting  Storage  Batteries 40 

Construction  of  Jump  Spark  Coil 22 

Diagrams  for  Wiring 81 

Distributers 32 

Dry  Batteries 36 

Dry  Battery  Installation .- 64 

Dynamos .  .  . 47 

Gap,  S'park 31 

Generators 47 

High  Tension  Magnetos 54 

Horsepower 74 

Horsepower  Ratings 75 

Ignition,  Jump  Spark 16 

Ignition.  Make-and-Break   4 

Ignition  System,  Installation 63 

Installation  of  Ignition  System '.  .  63 

Jump  S'park  Coil.  .  . , 17 

Jump  Spark  Coil  Action 25 

Jump  Spark  Coil  Construction 22 


Page. 

Jump  Spark  Ignition 16 

Magnetism    1 

Magnetos 51 

Magnetic   Primary   Igniters. 11 

Make-and-Break  Igniters   4 

Open  Circuit  Batteries 40 

Permanent  Magnets    2 

Plugs,  Spark 27 

Primary  Batteries   36 

Retarding  S'park   13 

Ilhumkorf  Coil   -. 17 

Sal  Ammoniac  Batteries .  .  .36,  38 

Secondary  Batteries   45 

Soda  Batteries 36,  41 

S'park  Advance   13 

Spark  Coil  Action 25 

Spark  Coil  Construction 22 

Spark  Coil,  Tump      17 

Spark  Coil,  Make-and-Break , *> 

Spark  Gap   31 

Spark  Plugs 27 

Storage  Batteries 45 

Switches 63 

Timers 32 

Troubles,  other  than  Ignition 68 

Troubles,  Testing  for 56 

Vibrating  Coil   £5 

Vibrator 18 

Volt 3 

Voltage,  Battery 43 

Voltage,  Magneto 51 

Voltage  of  Secondary  Current 21 

Water  in  Fuel 70 

Wet  Batteries 38 

Wiring  Diagrams SI 

Wiring  Installation 03,  65 


SUCTION  GAS 


By 
OSWALD  H.  HAENSSGEN 


Gas  Producers  have  begun  to  in- 
fluence largely  the  question  of  the 
economic  production  of  power.  In 
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several  years;  while  their  introduc- 
tion in  America  has  been  compari- 
tively  recent. 

Suction  Gas  Producers  and  Pro- 
ducer Gas  Engines  are  subjects 
requiring  special  knowledge  of  the 
conditions,  and  in  this  work,  by  an 
eminent  German  gas  engine  expert, 
these  subjects  are  fully  considered. 
The  work  is  for  the  manufacturer, 
designer  or  user  of  Suction  Gas  Pro- 
ducers and  Producer  Gas  Engines 

CLOTH.  9O  PAGES. 

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